a deferred created when stopListening is called, and that will
fire when connection is lost. This is not to be used it directly: prefer
the deferred returned by stopListening instead. (type: defer.Deferred)

A string describing the connections which will be created by this port.
Normally this is "TCP", since this is a TCP port,
but when the TLS implementation re-uses this class it overrides the value
with "TLS". Only used for logging.

A flag indicating whether the producer was registered as a streaming (ie
push) producer or not (ie a pull producer). This will determine whether
the consumer may ever need to pause and resume it, or if it can merely call
resumeProducing on it when buffer space is available.